Peripheral Arterial Disease and Risk of Atrial Fibrillation and Stroke: The Multi−Ethnic Study of Atherosclerosis

Study Questions:

Is the presence of peripheral artery disease (PAD) associated with an increased risk of atrial fibrillation (AF) and a subsequent risk of stroke?

Methods:

Exploring the Multi-Ethnic Study of Atherosclerosis, 6,568 patients with baseline ankle-brachial index (ABI) testing were followed. Presence of PAD was defined as having a baseline ABI <0.9 or >1.4. AF was identified through claims data, and an independent adjudication committee assessed all stroke events. Multivariate regression models were performed to assess the risk of AF and stroke when controlled for sociodemographics, cardiovascular risk factors, and other potential confounders.

Results:

At baseline, 774 (12%) participants had PAD. During a median follow-up of 8.5 years, 301 (4.6%) developed AF and 140 (2.1%) suffered a stroke. AF developed in 12/1,000 patient-years in PAD patients compared to 5.3/1,000 patient-years in non-PAD patients (p < 0.001). In the adjusted model, PAD patients were at increased risk of developing AF (hazard ratio [HR], 1.5; 95% confidence interval [CI], 1.1-2.0). Stroke developed in 140 (2.1%) participants, of whom 36 (26%) had PAD at baseline. In the adjusted model, PAD patients were at increased risk of developing stroke (HR, 1.7; 95% CI, 1.1-2.5). The risk of stroke did not change when the model included AF as a covariate because only one participant developed AF prior to developing a stroke in the study cohort.

Conclusions:

The authors concluded that patients with PAD are at increased risk of AF and stroke, but that the presence of AF does not appear to mediate the risk of stroke in this population.

Perspective:

This registry-based analysis confirms an association between PAD and the risk of stroke. It also confirms the association between PAD and the risk of developing AF. However, there was not evidence that risk of stroke in PAD patients can be attributed to AF. This study serves as a reminder that atherosclerosis is a diffuse disease. Clinicians should consider evaluating all vascular beds as potential targets of atherosclerosis in PAD patients.

Keywords: Ankle Brachial Index, Atherosclerosis, Atrial Fibrillation, Peripheral Arterial Disease, Stroke, Risk Factors, AHA Annual Scientific Sessions


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